[Python-ideas] (try-except) conditional expression similar to (if-else) conditional (PEP 308)

[Georg Brandl]

MRAB schrieb:
> Jan Kaliszewski wrote:
>>> Syntax Ideas:
>>>     Option 1:
>>>         x = float(string) except float('nan') if ValueError
>>>         op(float(string) except float('nan') if ValueError)
>> 
>> -0.5
>> I wouldn't mix up 'if' word with 'except' -- there are different concepts.
>> 
>>>     Option 2:
>>>         x = float(string) except ValueError: float('nan')
>>>         op(float(string) except ValueError: float('nan'))
>> 
>> +0.5
>> IMHO seems to be the best of the propositions. I'd add to it optional
>> as (like in present 'try:... except Exc as exc:...')
>> 
> Can there be multiple 'except's?
> 
>      reciprocal = 1.0 / float(string) except ValueError: float('nan') 
> except ZeroDivisionError: float('inf')

Don't over-complicate.  This proposal has a slim chance of success as it
is; piling on top isn't going to help.

IMO, any syntax that puts something other than the exception class after
"except" has zero chance.  The "except-then" is the most attractive to
me, but still doesn't read as naturally as "if-else".

Georg

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